BIOS is the firmware you see when you boot your system. You might have an operating system installed and if your hardware is fairly recent, it might appear that your system boots right to it. That’s not the case. The BIOS always loads first. Your BIOS normally has a setting that allows you to set the first boot device however, this is only if you’re running legacy BIOS. If you’re using UEFI BIOS, you won’t see this option. Here’s how you can set the boot device on UEFI BIOS.
There are two ways to set the boot device on UEFI BIOS. You can change the BIOS firmware to the legacy BIOS, or you can use the built-in option in UEFI BIOS.
UEFI Boot Device Options
Turn your laptop or desktop off, and then turn it on again. Before you get to your OS’ boot screen, you should see which keys you need to tap to get to your BIOS. There ought to be a second option that tells you which key to tap to get to the Boot options. These keys will differ for different systems. On a Dell laptop the key is F12. Google which key it is for your system.
When you tap this key, you will get an option asking you to choose which boot device you want to use. Make sure you’ve connected the device you want to use before you boot to this menu or it won’t show up in the list of devices you can boot from.
Use the arrow keys to select a device, and tap Enter to boot.
UEFI To Legacy BIOS
To change your BIOS from UEFI to Legacy, turn on your system and tap the key to get to the Boot menu. The key is different for each system but normally it’s the F2 key. If that doesn’t work, you can Google which key to tap for your system, or you can check our guide to access BIOS to find the right key.
The menu ought to have a dedicated Boot tab. Use the arrow keys to go to the Boot tab, and look for the Secure boot option. Disable secure boot and you ought to see the usual option for selecting the first boot device.
This should not have an impact on any OS you might already have installed. You should still be able to boot from your hard drive or SSD if you need to. Likewise, your data will be safe as well. Changing BIOS firmware rarely renders an OS unbootable and it does not result in data loss.